the first lady will also deliver remarks at the bill-signing. vice president joe biden will center.the new law george lettis will love more coming up tonight on 11 news at 11:00 p.m. much of the focus down in washington will be the investigation into the bombings at the boston marathon. howracie potts has more on washington is responding. more police presence. >> the memory of the victims in today's attack in boston. >> congress observing a moment of silence for boston's victims. the fbi and intelligence officials brief lawmakers on what they know about the explosion. >> the most important thing is that we get it right. we get the right information. >> the president sent an fbi team to boston, promising justice. >> we will find out who did this and hold them accountable. >> more security around the city. stations.s and metro the parade and fireworks for today's emancipation day celebration will go on. >> i want people to feel comfortable. come down and enjoy yourself. >> d.c. on high alert as washington tries to pin down the nature of the attack